1. Field of the Invention
The present invention relates to the field of the container handling apparatus, and more particularly to the field of apparatus for individually handling containers as may be used in container uncasing apparatus.
2. Prior Art
Various types of container handling apparatus are well known in the prior art. Of particular interest is the internal gripper apparatus of U.S. Pat. No. 4,032,185, as the preferred embodiment of the present invention comprises an improvement to that gripper. That patent discloses internal gripper apparatus for use in uncasers and the like for controllably gripping bottles or other containers from within for transport and release as desired. The internal grippers are spring-loaded to an outer position though automatically retract as required for insertion into the mouth of a container, gripping the container near the top, or at the ridge adjacent the top of the container characteristic of many containers. The grippers have an upward extending centrally disposed actuating member which may be slidably encouraged to a lower position to retract the grippers and release a container held thereby. The grippers provide relatively close axial positioning of the containers to provide the desired separation of containers on container handling apparatus, and further include supporting structure to allow retraction of the gripper on engagement with broken or inverted containers or other obstructions in the normal operation of the gripper apparatus.
Fabrication of certain major gripper components from plastic materials having high impact resistance and self-lubricating characteristics such as Delrin provides long, substantially maintenance-free life for the grippers. Also, by appropriately proportioning the grippers and perhaps allowing some settling of the containers onto a receiving conveyor, a simple, short duration release actuation of the gripper will provide positive releasing of containers handled thereby.
Also known in the prior art are grippers for retaining containers from within generally having some form of pneumatic apparatus, depending upon the actuation of a pneumatically expandable and contractable bladder in each gripper to provide the gripping and release functions. Such grippers generally operate satisfactorily, though result in certain complexities because of the requirements of a vacuum or pressure source as a prime mover, the connection of each individual gripper on a transport mechanism to the pressure or vacuum source, and the control of the pressure or vacuum source for individual grippers to provide the gripping and release at the appropriate points of progress of the transport system.
One form of mechanical case unloader is disclosed in U.S. Pat. No. 2,609,109. In this unloader a row of internal grippers is mechanically operated in unison by a single operating mechanism, providing substantially positive vertical motion and gripping action as a result of the unitary actuating mechanism.